Disperse dyeing with polymeric fatty nitrile solution

ABSTRACT

Polymeric materials of improved dyeability and other properties are provided which consist of polypropylene or polyester material and a small percentage of a nitrile which contains 20-75 carbon atoms and 2-4 nitrile groups in the molecule. Processes for preparing these improved polymeric materials and methods for dyeing these materials are also provided.

D United States Patent [1 1 [I 11 3,881,867

van Veersen May 6, 1975 1 DISPERSE DYEING WITH POLYMERIC [56] ReferencesCited FATTY NITRILE SOLUTION UNITED STATES PATENTS [75] Inventor:Gerardus Johannes van Veersen, 3,114,588 l2/l963 Lewis 8/172 Goude,Netherlands Primary ExaminerDonald Levy [73] Asslgneei Er s IndustriesCmcmnan Attorney, Agent, or Firm-John D. Rice; Gerald A.

Baracka [22] Filed: Jan. 29, 1973 App]. No.: 327,287

Foreign Application Priority Data Jan. 28, 1972 United Kingdom 4l79/72u.s. Cl. 8/169; 8/177 AB; 8/179 Int. Cl 006 5/04 Field of Search 8/169,177 AB, 179

[5 7 ABSTRACT 2 Claims, No Drawings DISPERSE DYEING WITH POLYMERIC FATTYNITRILE SOLUTION BACKGROUND OF THE INVENTION It is generally known thatcertain polymeric materials take up and retain most dyestuffs to aninsufficient extent. Examples of such polymeric materials arepolyalkylenes, more in particular poly-alpha-olefins such aspolypropylene and polyethylene, and furthermore polyesters. Thedifficulty in dyeing these polymeric materials has had a restrictingeffect on their applicability to fibres, mono-filaments and foils.

Various possibilities have been proposed to increase the capacity ofthese polymeric materials to take up and retain dyestuffs. Thus it hasbeen proposed to degrade the surface of the polymer slightly byoxidizing or radiation, by grafting or copolymerization and byincorporating suitable materials in the polymer. The incorporation ofadditives in the polymer is generally preferred because it avoids extramanufacturing steps. Moreover, the additive used may also'impartsecondary beneficial properties to the polymeric material.

SUMMARY OF THE INVENTION It has now been found that the capacity ofcertain of the above-mentioned polymeric materials to take up and retaindyestuffs can be improved by incorporation of an effective amount ofcertain dior polynitriles of higher molecular weight (defined andfurther herein below referred to as higher polynitrile) in the polymericmaterial. The invention thus provides polymers of improved dyeabilityand processes for the preparation of such polymers.

Improvement in the dyeability is of particular importance for polymericmaterial used in the manufacture of fibres and the invention thereforeprovides in particular a method for preparing improved polymeric materials such as polypropylene and polyesters.

DETAILED DESCRIPTION The improved polymeric materials according to theinvention belong to the class consisting of polypropylene, in particularcrystalline polypropylene, and polyester materials in which a smallpercentage of a higher polynitrile is incorporated together with thecustomary minor amounts of other additives. Copolymers and terpolymersof polypropylene or polyesters possessing properties that render themsuitable for use as fibre materials which are similar to thehomopolymers are regarded as obvious equivalents of polypropylene andpolyester respectively.

The amount of higher polynitrile incorporated generally ranges from afraction of a percent, say 0.5 calculated per 100 parts resin (p h r),to l5% (p h r) preferably 0.5-5 p h r. This range depends among otherthings on the nature of the polymeric material. In the case of certainpolyester materials incompatibility may arise when more than 3 p h r ofhigher polynitrile is incorporated. Incorporating too high a quantity ofhigher polynitrile may cause lowering of the melting point of thepolymer to an unacceptable extent.

The higher polynitrile may contain from 20-75 preferably 25-60 carbonatoms in the molecule and 2-4 nitrile groups. The presence of carbon tocarbon double bonds is not required but does not interfere either and upto two of these double bonds may be present in the molecule. A balanceof one nitrile group per -22 carbon atoms is particularly preferred,i.e., dinitriles containing 30-44 carbon atoms and trinitrilescontaining 45-66 carbon-atoms. In view of this balance the higherpolynitrile is conveniently prepared from naturally occurring fatty acidstarting materials, i.e., from saturated or unsaturated monocarboxylicacids containing 16-22 carbon atoms which are polymerized and thecarboxylic groups of which are subsequently converted into nitrilegroups. These preferred polynitriles thus contain a hydrocarbon groupwhich is identical with that of the polymerized fatty acid. Underpolymerized fatty acid is to be understood fatty acids which have beenpolymerized or coupled via e.g., styrene or a homologue thereof ordirect, optionally followed by hydrogenation of carbon to carbon doublebonds. These polymerization reactions are known in the art to yielddicarboxylic, tricarboxylic acids or mixtures thereof, sometimes alsocontaining a minor amount of higher polymeric materials. The unconvertedmonomeric starting materials are easily stripped off and the reactionmixture optionally separated into fractions consisting of dimers,trimers or higher polymers before the carboxylic groups are convertedinto nitrile groups. As stated above polymerized fatty acids can beprepared by heteropolymerization involving fatty acids and unsaturatedcompounds like styrene or homologues thereof and by homopolymerizationin which two or more fatty acid molecules are coupled.Homopolymerization of unsaturated fatty acids can be effected byheat-treatment usually in the presence of catalysts such asmontmorillonite clays and dimers, trimers and higher oligomers areformed. Fatty acids which can thus be polymerized are e.g., oleic,linoleic and linolenic acid, their positional isomers and homologuesthereof. Unsaturated fatty acids or mixtures thereof which contain l8carbon atoms in the molecule are readily available and then yielddimeric acids containing 36, trimeric acids containing 54 and tetramericacids containing 72 carbon atoms in the molecule and the correspondingpolynitriles.

Conversion of the polymerized fatty acid into the polynitrile can beeffected by reacting with ammonia and subsequent heating, therebydehydrating and forming the nitrile which can be used as such or afterfurther purification. Under dimer dinitrile is to be understood thedinitrile of dimeric fatty acid as e.g., dioleic acid, dilinoleic acidor dilinolenic acid and under trimer trinitrile the correspondingtrinitrile.

The higher polynitrile may be incorporated into the polymeric materialin various ways, e.g., by adding to the molten polymer, by coatingparticles of polymer and subsequently fusing into a melt. The particlescan be coated spraying or tumbling in a drum. The polymeric material isthen worked by conventional methods into sheets, foils, monofilaments orfibres. The incorporation of the higher polynitrile in the polymericmaterial frequently imparts better rheological properties to the melt,which then e.g., flows more easily in the extruder, thereby increasingits throughput.

The invention thus provides polymeric materials such as polyalkylenes,more in particular poly-alpha-olefins such as crystalline polypropyleneand polyethylene containing 0.5 to 15 parts per parts resin, preferably0.5-5 p h r of a higher polynitrile to which many dyestuffs will adheremore firmly and lastingly than to the corresponding fibres without thehigher polynitrile.

The polymeric materials according to the invention can be dyed undermild conditions at a relatively low temperature, i.e., below 100 C suchas e.g., those applied for natural materials like cotton and wool,yielding bright colored products. Many dyestuffs can be used when dyeingthe polymers according to the invention, including the majority of thosecustomarily used for cotton and wool, disperse dyestuffs and inparticular dyes containing basic nitrogen atoms such as aniline dyes.Some of these dyes tend to be unstable and discolor when exposed to useconditions; they lose their brilliancy and fade. Certain dyed polymericmaterials containing the higher polynitrile retain their brilliancy overprolonged periods even under conditions including exposure to daylight,rubbing and scouring so that the higher polynitrile in the polymerappears to stabilize these dyestuffs. In some instances the antistaticproperties of the polymer appeared to have been improved by thepolynitrile. The polynitrile also appears to increase the output of theextruder and facilitates the stretching process. Consequently accordingto the invention in addition to improving the dyeability one or more ofthe advantages mentioned above may be secured.

EXPERIMENTS Preparation of dimerdinitrile.

One thousand g of polymeric fatty acid predominantly consisting ofdimeric fatty acids (Empol 1022, manufactured by and commerciallyobtainable from Unilever-Emery N.V., Gouda, The Netherlands) wereintroduced into a four-necked flask. Two g of zinc oxide and 5 g ofhypophosphoric acid (50%) were added, the flask was placed in a fumecupboard and equipped with: (a) a fast rotating stirrer, (b) athermometer, (c) a gas inlet tube with the open end just below thestirrer, (d) a condenser cooled with water of 6590 C, which wasconnected to a receiver with an open gas outlet.

Nitrogen was introduced and the flask and contents heated to 150 Cwhilst stirring at this temperature, the introduction of ammonia throughthe gas inlet tube was started and heating was gradually increased to275-280 C.

Unreacted ammonia together with reaction water condensed partially inthe condenser or escaped. Ammonia soap formed in the condenser wasremoved mechanically when it tended to clog the condenser. Bubblingthrough ammonia was continued for 3-4 hours and terminated when the acidvalue of the reaction mixture was below 0.5 and the amide content below0.1 milli-equivalents per gram.

The reaction product was then subjected to a mm mercury (absolute)vacuum at 200 C for minutes. cooled in vacuo to 80 C and filtered. Thusdimer dinitrile, a light amber colored viscous liquid in a yield of 91%,n 1.4787; b.p. 310 C/7 mm Hg, acid value 0.12, amide content 0.0027milli-equivalents per gram and an ash content of 0.01% was obtained.

PREPARATION OF TRIMER TRlNlTRlLE In the same was as described for dimerdinitrile trimer trinitrile was prepared from Empol 1040, manufacturedby and commercially obtainable from Unilever-Ernery N.V., Gouda, TheNetherlands, a mixture of polymeric fatty acids mainly consisting oftrimeric and higher oligomeric fatty acids. Formation of ammonia soap inthe condenser, however, hardly occurred. Thus trimer trinitrile, n1.4898, a dark amber colored viscous liquid, was obtained in a 98%yield, b.p. 350 C/7 mm Hg, acid value 0.26, amide content 0.026milliequivalents per gram and an ash content of 0.1%.

EXAMPLES I 4 Several samples consisting of 100 parts of polypropylene(Carlona PM 61 naturel" ex Rotterdam Polyolefin Company, Pernis, TheNetherlands) were milled in a two-roller mill at a friction of 1 1.3 ata temperature between and C for 20 minutes with and without addition ofa dimer dinitrile and trimer trinitrile described above in quantities asindicated below. Dimer dinitrile and trimer trinitrile were preparedrespectively from Empol 1022 and 1040 dimer and trimer acidsmanufactured by and commercially obtainable from Emery Industries, Inc,Cincinnati, Ohio by polymerization of unsaturated fatty acids.

Blank Ex. Ex. Ex. Ex.

Parts polypropylene 100 100 100 100 100 Parts dimer dinitrile (b.p. 310C/7 mm Hg) 5 Parts trimer trinitrile (b.p. 350 C/7 mm Hg) 5 3 1 CompoundOutput g/hr Increase 12 Blank 123 Ex. 1 134 12 Ex. 2 143 19 Ex. 3 134 12Ex. 4 134 12 The mixture of Example 3 excelled in ease of processing,extrusion and subsequent stretching.

After the continuous polypropylene monofilament thus obtained had beencooled and collected on a spool, it was unrolled and stretched bypassing over a Pyrovane Honeywell heating plate having a temperature of125 C. Each of the monofilaments was thus uniformly necked in apredetermined place and stretched according to stretch ratios between 13 and 1 4 and wound up into skeins. The original monofilament of 315denier was thus converted into a monofilament of 100 75 denier.

Dyeing of the skeins of the blank and the compounds according toExamples 1 4 was carried out in a dye bath containing 500 mg of dye asindicated below per litre of water.

Dyestuff Color Index Color obtained Reference Auramine ON ISO 41000bright yellow Victoria Blue BN I50 44045 intense blue Rhodamine BN 45045170 red Methylene Blue 2 BN 150 520l5 bright blue Dyeing took placefor one hour at 80 C; the skeins were then washed with distilled waterand dried at room temperature. Visual judgment of the dyed filaments oncomparison with the blanks showed that for all dyes the variouscompounds containing the higher polynitrile showed intenser colors andtherefore had a better dye retention than the blank.

In this series of Examples dye retention decreased in the sequence 1, 2,3 and 4.

EXAMPLES 5 6 Blank Ex, 5 Ex. 6

Parts polyolefin 100 100 Parts dimer dinitrile (b.p. 3l0 C, 7 mm Hg)Parts trimer trinitrile (b.p. 350C, 7 mm Hg) Dyestuff Color Index ColorObtained Reference Auramine ON 150 41000 bright yellow Victoria Blue EN150 44045 blue Rhodamine RN 450 45 l red Methylene Blue BN lSO 52015bright blue The blank had taken up a negligible amount of dye, showingpale colors, whereas the sheets containing the higher dinitrile werebright-colored.

What is claimed is:

1. A method for dyeing polypropylene or polyester materials in the formof sheets, foils, monofilaments, or fibers comprising treating saidmaterials containing an effective amount of a polymerized fatty acidnitriles containing 20-75 carbon atoms and having 2-4 nitrile groupswith an aqueous medium containing a dyestuff.

2. A method according to claim 1 in which the polypropylene or polyestermaterial is dyed with a disperse dye at a temperature below C.

1. A METHOD FOR DYEING POLYPROPYLENE OR POLYESTER MATERIALS IN THE FORMOF SHEETS, FOILS, MONOFILAMENTS, OR FIBERS COMPRISING TREATING SAIDMATERIALS CONTAINING AN EFFECTIVE AMOUNT OF A POLYMERIZED FATTY ACIDNITRILES CONTAINING 20-75 CARBON ATOMS AND HAVING 2-4 NITRILE GROUPSWITH AN AQUEOUS MEDIUM CONTAINING A DYESTUFF.
 2. A method according toclaim 1 in which the polypropylene or polyester material is dyed with adisperse dye at a temperature below 100*C.